My 12 day old will eat and then acts hungry again an hour later but when she is done she projectile vomits everything. She is drinking formula and expressed breastmilk. Sometimes mixed and sometimes one without the other. She has done it with both types of milk. However we do notice that sometimes as soon as she is feeding on formula she starts farting and farting while eating?

do we just keep feeding her as long as she acts hungry even though she ends up puking it or do we cut her off?